The biology behind the problem is unforgiving. In genetically susceptible individuals carrying the HLA-DQ2 or HLA-DQ8 variants, dietary gluten triggers an adaptive immune cascade in which the enzyme tissue transglutaminase-2 chemically modifies gliadin peptides, provoking T-cell-driven destruction of the small intestinal lining. The result is villous atrophy and crypt hyperplasia, which shrink the absorptive surface of the gut and compromise the epithelial barrier. Diagnosis still requires positive serology, typically tissue transglutaminase IgA antibodies, together with a small-intestinal biopsy demonstrating villous damage, yet many people who self-diagnose or drift onto gluten-free diets have never been formally tested. Survey data suggest a global prevalence of about 1.4 percent, but an iceberg effect means most cases remain undiagnosed, and athlete-specific figures are almost nonexistent.

The numbers that do exist are telling. In a survey of 141 NCAA collegiate athletes, roughly 2.8 percent reported a physician diagnosis of celiac disease, while about 11.3 percent scored above the threshold for celiac-consistent symptoms, yielding odds of high-symptom status nearly 18 times higher than a general-population benchmark. The authors of the review caution that these figures rely on self-report, were drawn from a small convenience sample skewed toward white Midwestern athletes, and were compared against general-population rather than age-matched non-athlete controls. Still, the signal is hard to ignore, particularly because intense endurance exercise independently raises intestinal permeability, elevates serum zonulin, and upregulates the pore-forming tight junction protein claudin-2, mechanisms that converge with celiac pathology and could amplify risk or mask symptoms in genetically susceptible athletes through what researchers call Exercise-Induced Gastrointestinal Syndrome.

Even after diagnosis, the challenges multiply. The gold-standard treatment, a strict gluten-free diet, is nutritionally treacherous for people whose energy demands can reach 50 to 80 kilocalories per kilogram of body weight per day in endurance sports. Gluten-free products are frequently made from refined rice, tapioca, and potato starches, carry a higher glycemic index than wheat equivalents, and lack the iron and calcium fortification of conventional foods. Cross-contamination is a persistent hazard: studies of restaurant meals labeled gluten-free have found that roughly a third contain detectable gluten, and sensitive patients can suffer mucosal injury at daily exposures as low as 10 milligrams. The socioeconomic burden compounds the problem, with gluten-free foods costing 76 to 518 percent more than conventional equivalents in the United Kingdom, roughly double in Saudi Arabia, and up to 259 percent more on average in the United Arab Emirates, a burden that falls hardest on young, underfunded athletes who report food-related anxiety, social isolation, and meals skipped before competition.

The nutritional consequences are measurable and severe. Iron deficiency anemia affects up to 82 percent of celiac patients, and only about half restore their iron stores within a year of starting the gluten-free diet. Exercise compounds the deficit because the hormone hepcidin, which blocks iron absorption, remains elevated for up to six hours after training, cutting fractional iron absorption by more than a third. The review recommends timing iron-rich meals and supplements to the early morning, avoiding the three-to-six-hour post-exercise window, and pairing plant-based iron sources with vitamin C. Vitamin D deficiency, present in 8 to 88 percent of celiac patients, carries a staggering 23.3-fold higher risk of fifth metatarsal stress fractures at low serum levels, prompting suggested intakes of 2,000 to 6,000 IU per day for affected athletes. Calcium, magnesium, zinc, and B vitamins follow similar patterns of depletion driven jointly by malabsorption and the poor nutrient density of gluten-free substitutes.

The review also ventures into emerging territory. Sucrosomial iron formulations are preferred for athletes who cannot tolerate ferrous sulfate, and magnesium citrate or glycinate outperform oxide, whose bioavailability is a mere 4 percent. Genetic polymorphisms in the vitamin D-binding protein and receptor genes may explain why some athletes need substantially larger doses to reach the same serum 25-hydroxyvitamin D target of 30 to 50 nanograms per milliliter. On the supplement front, multi-strain probiotics containing Bifidobacterium breve and Lactobacillus plantarum reduced gastrointestinal symptoms 29 percent more than placebo in meta-analysis, while the alanyl-glutamine dipeptide, which survives gastric digestion and upregulates the tight junction proteins claudin and occludin, shows theoretical promise for a gut battered both by disease and by exercise-induced ischemia, though no trial has yet tested it in celiac athletes.

Perhaps the most underappreciated dimension is psychological. A meta-analysis found that people with celiac disease face roughly six-fold higher odds of anxiety and more than double the odds of depression, and collegiate athletes with more celiac-consistent symptoms reported poorer quality of life across physical, psychological, social, and environmental domains, along with greater depression and perceived stress. Childhood celiac disease carries a 19 percent increased risk of psychiatric disorder that persists into adulthood. Disordered eating is another red flag, with a pooled prevalence of nearly 9 percent and a significantly elevated risk of anorexia nervosa, a dangerous overlap in athletic populations where restrictive eating is already common. Even cognition is affected: neuroimaging studies have documented slower reaction times and white matter microstructural changes, the so-called brain fog, with direct implications for tactical decision-making and reaction-time precision in sport.

To bring order to this fragmented picture, the authors lay out a monitoring architecture that spans serology, biochemistry, and performance. Tissue transglutaminase IgA with total IgA remains the first-line screen, and clinicians are urged to test athletes presenting with unexplained fatigue, recurrent infections, refractory iron deficiency, or disproportionate stress fractures, noting that classic gastrointestinal symptoms may be absent in up to half of atypical cases. HLA-DQ2/DQ8 genotyping, with a negative predictive value above 99 percent when both alleles are absent, helps when athletes have already gone gluten-free. Blood sampling should be standardized, ideally in the morning after at least 48 hours of rest, to control for exercise-induced analytical variation, a detail routinely neglected in clinical practice. Dual-energy X-ray absorptiometry tracks bone mineral density and distinguishes genuine fat-free mass recovery from the fat gain and sarcopenic pattern that has been observed after a year on a gluten-free diet, while countermovement jump, handgrip strength, VO2 max, heart rate variability, and patient-reported symptom and quality-of-life scales complete the functional picture.

The review is candid about its limits. It is a structured narrative review conducted under the SANRA quality framework, not a systematic review with risk-of-bias assessment or meta-analysis, and much of its practical guidance extrapolates from the general celiac population, athletic populations without the disease, and mechanistic studies rather than from trials in biopsy-confirmed celiac athletes, of which there are almost none. Its recommendations should therefore be read as hypothesis-generating and practice-oriented rather than graded clinical guidelines. Still, the authors argue that no existing review has previously woven nutritional assessment, supplementation, and performance monitoring into a single athlete-centered framework, and they call for randomized controlled trials with biopsy-confirmed enrollment, adherence-verified comparator arms, and stratification by sport type, sex, age, and mucosal healing status.

The broader message resonates beyond the locker room. Celiac disease sits at the intersection of immunology, gastroenterology, exercise physiology, and psychology, and athletes amplify every one of those variables. If future research confirms that the physiological stress of training lowers the threshold for disease expression in genetically susceptible individuals, sports medicine will need athlete-specific epidemiology, screening checklists, and possibly an international registry to track adherence, biomarkers, and performance over time. For now, the review offers coaches, dietitians, and team physicians a practical warning: when an athlete’s engine keeps misfiring for reasons that training loads and talent cannot explain, it may be worth checking whether the fuel line itself is under attack.

Subject of Research: Integrated nutritional and performance monitoring for athletes with celiac disease

Article Title: An Integrated Nutritional and Performance Monitoring Framework for Athletes with Celiac Disease: A Structured Narrative Review

Article References: Yamani, O. B., Alghamdi, M. M., Zagzoog, A. M., Noorwali, E. A., Alotaibi, R. A., Alghannam, A. F., Aljaloud, K. S., Aragon, A. A., & Elsahoryi, N. A. (2026). An Integrated Nutritional and Performance Monitoring Framework for Athletes with Celiac Disease: A Structured Narrative Review. Current Research in Food Science, Article 101568. https://doi.org/10.1016/j.crfs.2026.101568

Image Credits: AI Generated

DOI: Not provided

Keywords: celiac disease, athletes, sports nutrition, gluten-free diet, iron deficiency, vitamin D, intestinal permeability, micronutrients, performance monitoring, probiotics, glutamine, athlete health

The authors frame their work against a backdrop of mounting concern. A 2024 umbrella review in the BMJ concluded that greater dietary exposure to ultra-processed foods is associated with a higher risk of adverse health outcomes across the lifespan, with the evidence for cardiometabolic and mental health effects rated convincing or highly suggestive. A subsequent systematic review of 104 prospective studies found that 92 demonstrated an association between an ultra-processed dietary pattern and increased risk of chronic disease in adults. Ultra-processed foods have also been implicated in significant diet-related environmental impacts, and limiting them has been identified as a strategy to advance both human health and environmental sustainability. For athletes, who often consume large quantities of formulated products, these findings raise uncomfortable questions.

Central to the review is the question of classification. The dominant framework, the NOVA system developed by Monteiro and colleagues, sorts foods into four groups based on the nature, extent and purpose of processing: unprocessed and minimally processed foods, processed culinary ingredients, processed foods, and ultra-processed foods. Sports foods, by virtue of their formulation with protein isolates, maltodextrins, emulsifiers, flavour enhancers and other ingredients rarely found in domestic kitchens, typically fall into the ultra-processed category. Yet NOVA judges foods solely on their degree of processing and additives, not on their nutritional value, performance utility or environmental footprint, a limitation the authors argue is particularly problematic for athletes whose needs differ sharply from those of the general population.

The classification system is not without controversy. The review catalogues numerous categorisation anomalies: plain yoghurt is minimally processed, some fruit yoghurts are merely processed, and flavoured yoghurt is ultra-processed, while homemade fries and certain packaged corn chips can share the same category. Even food and nutrition experts disagree when classifying products using NOVA, and manufacturer reformulations can shift a product between categories over time. Alternative systems such as Siga, which offers finer gradations from unprocessed foods to ultra-processed products with multiple markers of ultra-processing, address some criticisms but have their own gaps. A new formulation and processing food index developed by an international task force may eventually refine the picture, but for now athletes and practitioners must navigate imperfect and sometimes contradictory tools.

On the question of awareness, the review found a striking research void: no published studies have examined athletes’ knowledge or understanding of ultra-processed foods. Evidence from the general population suggests familiarity with the term does not translate into accurate recognition. In a UK study, only 13 percent of participants correctly categorised all ultra-processed foods shown, and confidence in identifying them far outstripped actual ability. Even among dietitians, more than half were unfamiliar with NOVA, and fewer than a quarter correctly classified many grain foods. Given that sports dietitians are well placed to influence athlete food choices, these knowledge gaps matter, the authors argue, because practitioners cannot guide athletes on products they themselves struggle to classify.

What the review did find is a consistent picture of why athletes choose these products. Convenience and performance dominate. Among 1,145 athletes surveyed in Ireland, sensory appeal, food and health awareness and performance were the leading determinants of food choice, while sustainability considerations ranked in the lowest quartile. Ultra-endurance athletes prioritised products that avoid gastrointestinal discomfort, provide energy and can be easily carried and consumed. Australian athletes and exercisers reported improved performance, endurance and recovery as key reasons for using sports foods, with cost and taste the main deterrents. German endurance athletes noted that while everyday foods were generally preferred, sports foods were sometimes more convenient or time-saving during training. Interviews with English Premier League players revealed that upbringing, club culture, coaches, teammates and media all shape dietary practices.

Consumption data, though sparse, suggest frequent use. In an Australian survey, nearly all athletes and exercisers reported consuming sports foods within the previous 12 months, and roughly 70 percent of German-speaking triathletes, cyclists and runners used a combination of commercial sports nutrition products and everyday foods. Studies of European endurance runners, Romanian soccer players and Spanish cyclists and triathletes all documented regular intake of processed and ultra-processed items, though the authors caution that inconsistent classification methods, small samples and questionnaires that capture only narrow food categories make comparisons difficult. Notably, no study has yet quantified ultra-processed food intake as a percentage of total energy intake in athletes, the metric most relevant for assessing health risk.

The review also challenges a cherished assumption of sports nutrition: that a food-first approach automatically reduces ultra-processed intake. When the authors classified the everyday food swaps suggested in Australian Institute of Sport resources using NOVA, they found that each sports food category included replacement items spanning multiple processing categories, including some that are themselves ultra-processed. An Australian analysis of the packaged food supply found that 40 percent of core foods were ultra-processed, meaning that swapping a sports gel for honey or a bar for a muesli bar may not meaningfully change processing exposure. Meanwhile, a systematic review found little or no difference in endurance performance between carbohydrate supplements and ordinary foods such as bananas, raisins or potatoes, and a Spanish case study showed that an ultra-endurance event could be fuelled entirely with sustainable, minimally processed foods, though the practicality of doing so outside controlled settings remains untested.

On health and environmental impacts, the evidence in athletes is thin. Only one study has examined high ultra-processed food consumption and fitness measures in athletes, finding no differences in anthropometrics or cardiovascular fitness among elite basketball players but altered gut microbiota, with confounding from suboptimal carbohydrate and high fat intakes. No studies have linked sports food consumption to health outcomes in athletes or the general population. Yet athletes may carry a larger environmental food footprint than the general population because of higher total energy and protein needs, and data from Turkish elite athletes showed higher greenhouse gas emissions and water footprints strongly tied to red meat and animal protein consumption. The authors call for research into the prevalence and patterns of sports food and ultra-processed food use, their effects on athlete health and performance, and how dietitians can help athletes optimise nutrition strategies that support performance, personal health and planetary health alike.

Subject of Research: Ultra-processed food and sports food use, awareness and impacts among athletes

Article Title: Ultra-processed Foods and Athletes: Current Insights on Classification, Use, Awareness, and Impact—A Narrative Review

Article References: Ultra-processed Foods and Athletes: Current Insights on Classification, Use, Awareness, and Impact—A Narrative Review. (n.d.). https://doi.org/10.1186/s40798-026-01098-7

Image Credits: AI Generated

DOI: 10.1186/s40798-026-01098-7

Keywords: ultra-processed foods, sports foods, athletes, sports nutrition, NOVA classification, planetary health, food-first approach, athlete health, sustainability, dietitians, performance nutrition, food processing